Effect of SiO₂ Particle Size on Optical Properties of TiO₂-SiO₂ Nanocomposite Thin Films

Abstract

TiO 2 -SiO 2 thin film system is known to be very attractive to use for photocatalytic and display applications. In this study, TiO 2 -SiO 2 nano-composite solutions were prepared by adding colloidal solutions consisted of different SiO 2 nano-particle sizes (7-50 nm) into TiO 2 powder-dispersed solutions. TiO 2 -SiO 2 thin films on glass substrates were fabricated by the dip-coating technique and their crystal structure, surface morphology and photocatalytic properties were investigated as a function of SiO 2 particle size. While the SiO 2 particle size had little influence on the crystal structure of thin films, the photocatalytic activity and anti-reflectance (anti-glare) characteristics were found to be dependent on the SiO 2 particle size. This result could be explained in terms of surface characteristics and the order of degradation of methylene blue under UV light irradiation.